Plaster and lath unit



Oct. 26,1954 J. J. THOMAS PLASTER AND LATH UNIT Filed May 12, 1951 Patented Oct. 26, 1954 UNITED STATES PATENT OFFICE i claim. l

This invention relates to combined plaster and lath units, both being in sheet form and adapted to be nailed in place.

Both Wall and ceiling plastering entails considerable expense and are difcult to do. In both instances, the conventional procedure is to nail lathing in place and then to apply the wet plaster. While the invention relates to both uses, it is discussed herein principally with reference to wall plastering.

The principal objective of this invention is to provide a combined plaster and lath unit in sheet form that can be nailed directly to the studs and that requires the application of wet plaster only for the purpose of sealing the joints and nail holes. Another important objective is to provide an inexpensive lath unit in sheet form that can be quickly and easily nailed in place to lessen the time and expense in preparing a room for plastering and that is particularly adapted to facilitate the application of wet plaster.

1n accordance with this invention, a lath unit consists of a compressible sheet having its outer face corrugated and preferably coated with pitch or its equivalent. A combined unit employs such a lath unit as a backing and includes a plaster layer 'formed thereon and anchored thereto by the corrugated face thereof and by any bonding lay er employed. The plaster layer is also formed with nail holes and these are preferably counterv sunk to receive compressible means, such as washers or sleeves of rubber-like material, to protect the plaster from being cracked as the combined units are nailed in place. The compressible nature or the backing also cooperates to protect the dry plaster from being damaged during the nailing operation and from stresses otherwise imposed by slight irregularities in the stud surfaces to which the combined units are anchored.

The invention thus makes it possible to provide Wall and ceiling plaster in the form of dry sheets that are relatively light in weight. Such units enable a wall or ceiling to be completed quickly and easily since they may be saWed to t, where necessary, and after they are nailed in place it is only necessary to seal the joints and nail holes with Wet plaster.

In addition to the principal features of the invention to which reference has been made, the

accompanying drawings also illustrate other of its novel features and advantages. In the drawings,

Fig. 1 is an elevation showing combined plaster and lath units secured to studs.

Fig. 2 is a section on a plane indicated by line 2 2, and

Fig. 3 is a fragmentary section, on an enlarged scale, on a plane indicated by line 3-3 in Fig. 2.

In the embodiment of the invention illustrated by the drawings, reference is first made to the backing, indicated generally by the numeral 5, as it may be used by itself as a lath unit.

The backing 5 is a composite sheet consisting of a corrugated paper layer 6 having flat paper sheets 'I and 8 anchored to its faces. The sheet 'I is coated with a fire resistant paint, suggested by the numeral 9, and a corrugated paper I0 is secured to the sheet 3. The exposed surface of the corrugated layer IG is the outer face of the backing and has coat II of pitch or the equivalent to ensure efficient bonding of the plaster to the backing.

The combined unit has a layer I2 of plaster deposited on the backing 5 which is locked thereto by the corrugated layer IIi and its pitch coat II. The layer I2 is formed With a plurality of nail holes spaced to correspond to the spacing of the studs I3 to which the unit is to be nailed.

These holes are countersunl; to provide shoulders Id. Each hole thus may receive a sleeve or washer I5 of rubber-like material that seats against the shoulder lil. Nails I6 of the type having a flange I'I intermediate their ends may be most advantageously used in nailing the combined units in place because the flanges I'I engage the ccrnpressible washers I5, which serve as cushions to prevent the shock of hammer blows from cracking the dry plaster layer I2 as the nails are driven into the studs.

In this connection, it will be appreciated that, in wall use, the channels of the corrugated layer IIJ are horizontally disposed. For all uses, the backing 5 is suiciently compressible to protect the dry plaster coat from being cracked during the nailing operation or from being stressed as might otherwise result from minor irregularities in the surface defined by the face of the studs I3 to which the units are nailed.

In practise, the combined units are of a size that is convenient to handle and that ensures that the adjacent ends of adjacent units may be butted together on selected studs. Where required, the units may be sawed to fit corners, thus ensuring maximum economy in use. After each unit has been nailed in place, the edge thereof against which another unit is to butted is coated with wet plaster thereby to provide means to seal and conceal the joint. Such other unit is then nailed in place and after the wall is completed it is finished by sealing and ooncealing the nail holes with wet plaster as indicated at I8.

The backing 5 is an efficient thermal insulator and its use as a lath unit is advantageous for that reason and because of the ease with which it may be nailed in place and Wet plaster applied thereto.

What I therefore claim and desire to secure by Letters Patent is:

A combined plaster and lath unit to be nailed. in place, said unit comprising a backing sheet including layers of corrugated paper and an intermediate at paper sheet to which adjacent ridges of said layers are bonded, and a dry layer of plaster anchored to .and carried by one of the layers of the backing sheet, said plaster layer having a plurality of countersunk nail holes eX- tending through it, and a rubber Washer seated in the countersunk portion of each hole and engagea-ble therewith to provide a cushioned connection between said plaster layer and each nail by which the unit is attached.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 282,167 Cogswell July 31, 1883 649,363 Ryan May 8, 1900 1,399,455 Armstrong Dec. 6, 1921 1,657,193 Beshers Jan. 24, 1928 1,711,026 Kline Apr. 30, 1929 1,772,686 Rahr Aug. 12, 1930 1,787,453 Murray Jan. 6, 1931 2,120,644 Harper June 14, 1938 2,140,226 Harrap Dec. 13, 1938 2,167,998 Reid Aug. 1, 1939 2,405,527 Skolnik Aug. 6, 1946 

